Method of separating feldspar and quartz



F. P. KNIGHT AND J. T.SHIMMIN.

' METHOD OF SEPARATING FELDSPAR AND QUARTZ.

APPUCATION FILED JUNE22, 1921.

1 4 4";974 I Patented Jan. 31,1922

7 CRUDE ORE onus/1m .STORA EBINS I AUCOMA'JTIC FEEDER coMMm/rsfi 7 SIZINGWMACHINE OWE/z:

k comm/vars y IlI/ASHING TABLE FELQSPAR UARTZ MSTE Ol/ DRIER STORA a: or V MARKET C OMM/NUTE)? s/znve, MACH/N58 ovffifslzz UNDERSIZE' conglomerate, employed for separating the commercially mum:

. Manchester, Massachusetts,

' of much of the valuable. minerals as is,

' um'rizu sT Tssf PATENT OFFICE.

or mcnns'rnn, mssacnusn'r'rs, JOHN T. snnmm, or

sarnsnmum assreuon 'ro sun xmonr.

P. KNIGHT, BUBLEY, NEW MEXICO;

unrnon' or snruwrme runsrm aim cum-r2.

Specification of Letters Patent. application fled June 22, 1921. Serla1 No. 419,591, v

by continuous method the-crystalline aggro To all whom it may concern:

gate of the ores and matrices containing Be it known that we, FRANK P. Kmon r a citizen of the United States, residing at county of Essex, and State of.

and JOHN T. SHIMMIN, -a residin at the ores be taken directly from the mine or recovered from the dumps, the method being citizen of the United States, effected in such manner that the feldspar feldspar and quartz, as awhole, whether- Patented J a n.31, 1922 f v and quartz will be recovered as refined se Hurley, county of Grant, and State of ew' Mexico, have invented certain new and usearate products in a single operation, there. y

ful lmlprovements inMethods of Separating Fe dspar and Quartz; and. we do hereby declare the followin to be a full, clear, and exact description 0% the invention, such as will enable others skilled in the art to which it appertains to make and use the same,

The invention relates to the novel process of separating feldspar and quartz as these elements occur in various natural matrices and ores, and simultaneously eliminating therefore, other mineral constituents and impurities so quence of these circumstances, it has been that the feldspar and quartz are'recoveredgenerally accepted as a fact that feldspar separately and in. any desired degree of and quartz are incapable of mechanical separation .by any of the well known devices purity, as will be more particularly pointed out in the annexedspecification, which is employed for separating other mineral products, which differ among predicated by way of an exampleupon the separating plant illustrated schematically in cific gravity to a sufiicient the accompanying drawing.

The usual occurrence of feldspar "in nature is in the form of deposits or dikes in whichthe feldspar is associated with quartz. and various other minerals and impurities, as a' and the methods heretofore valuable minerals and greatly reduci'n the costs of mining and separating them aslrerefitofore practiced. a

quartz are substantially the same and do not --vary insufiicient degree to permit'of separation, either in whole or in part, by the and all'attempts at such separation have,

degree to enable and concentrating methods in vogue. Thereand quartz from ores containing these minerals has beenv limited exclusively to the. wasteful method f hand select1on,.

' from 20 to 40. percent erals, and even the roducts thus recovered are frequentlyunfit or commercial use without further treatment becauseof impurities of. the. admixtures of "being present in practically inseparable proportions in the hand-selected ore or matrix}.

valuable products from the natural aggregate, containing feldspar and quartz, have been by means of hand selection or cobbing, or sorting the broken mass for the recovery practicable by such primary conditions, the firstI being the posthe reject or waste, because of the impracti- .sibility of so flrcomminuting *the ore, or

cability of picking themout. Large pro-.

portions of the larger crystals are also lost at the-several fiuneral constitand quartz t uentswill be larger masses into small sizes for practicable individual particles, that; is

hand selection, and all portions of the minerals smaller than the range of sizes and? uartz, such comminntionwill result in 1 racticable for hand selection go into the rf an ixture of substantially pure' granules ect and are lost to the industry, and are ac-- of feldspar on the one hand. and.'substancumulating in dumps at the 'mines. The

primary object of the invention is to handle,

usual processes of mechanical concentration,

themselves-m spe- I 1 '80 them-to respondto' the various separating.

whic does'not admit of the recovery of mom than of the desired min mineral conglomeratelcarrymg the feldspar 'tially pure granules of quartz on the other; the second being predicated. on the inflexible greatly increasing the recovery of 'these" The specific gravities of feldspar and.

resulted" in failure. In consefore, the recovery or separation of feldspar the desired minerals elements of the I to sayyin the of; admixtures of feldspar," I I The present invention is based upon two.

I Na

natural laws that the two minerals, feldspar and quartz, have very marked differences in fracture and cleavage, the granules produced in crushing or comminuting them retaining their respective and peculiar properties of cleavage and fracture even to the remotes-t practical sub-division or corn minution. Feldspar, that is, orthoclase, microcline, and albite, is distinguished by monoclinic and triclinic crystallization with prismatic angles closely approximating and 120 degrees. These several forms of the mineral feldspar cleave in two directions in parallel planes, parting more easily in one set of planes "than in the other, thereby affording flat surfaces parallel with each other in grains that are broader and longer than they are high, and with sharp angles and Wedge-shaped sections on one-half of their edges.

The mineral quartz, or silica, is distinguished by its concoidal fracture and entire lack of regular lines of cleavage, so that when the mineral is broken up into granules,

'or reduced to a state of comminution, the

individual particles have substantially the same dimensions as to length, breadth and thickness, that isto say, quartz grains, of whatever size, average as high as they are long or wide. These individual characteristics, as to general shape and fracture of the granules or particles of feldspar and quartz, cause the particles or granules of the same size, of the respective minerals, to move at different rates over arelatively smooth surface under the influence of an impelling force, due to the difference in the resistance or opposition to movement, that is to say, the uniformly sized particles of quartz, generally concoidal in form, will move faster-over the surface than would.

granules of the same size of feldspar, which latter interposes fiat surfaces and sharp angles to-the supporting surface and would, therefore, oppose a larger element of resistance to movement under the same impelling force than would the quartz granules, with the result that the granules of quartz will collect in stra-taor bands on onesection of the surface, while the slower moving granules of feldspar will collect in a different area or band. 7

\Ve have found that by crushing and comminuting the ores and matrices containing feldspar and quartz, as a whole, down to the proper size grains to cleave the feldspar and quartz from each other, and incidentally to divide the other mineral matters and impurities from the quartzand feldspar, and from each other, it is possible to divide ponderable portions of the resulting mass into classes or. grades of substantially the same size grains, the various grains being intermixed, but individually consisting of practically pure quartz, pure feldspar,

nae tart etc. After the mass has thus been sized, classified or graded, the individual grades are separately treated on an inclined plane surface under a sheet of moving water, the inclination of the surface and the rate of fiow of the water being so regulated that increased uniformity and purity than has been 'possible of realization with any method. of separation heretofore known; It has been found in practice that with a mass of grains of substantially the same size and specific gravity being transported on a slightly inclined surface by a gently moving current of water, the lag of the grains on the surface will vary in accordance with the resistance offered by the grains by reason of their shapes. The quartz grains, being as high as they are wide or long, will be rolled over readily, by the moving current, and will be assorted in a band by themselves.

The feldspar grains, having flat surfaces,

conforming closely to'the plane on which they lie, and having wedge-shaped ends also to oppose the current, and being of less height than length and breadth, will oppose a materially greater resistance of movement by the fiowingwater than the quartz grains and will consequently lagbehind the latter and be assorted. into a separate class or band. Similarly the other mineral constituents, as well as-the impurities in the comminuted ore mixture, all of which are in substantially uniformly sized classes, will congregate in different areas and be separated from both the band of feldspar and the bands of quartz. If a differential movement, generally similar to that typical of concentrating machines, be imparted to the inclined surface or table, and so regulated as to move the resultant band's forward and beyond the influence of the sorting liquid stream, these two factors or forces may be caused to work in conjunction, so that the mineral constituents indicated will first be sorted into separate bands and said bands advanced over the surface of the table to (collected while the undesired elements and impurities may waste.-

We have found that several of the types of table concentrators, well known in the be discharged as tailing's or may be adapted to'make the separation con templated by thepresent invention. The inclination of the table and the rate of flow ofthe water thereover to effect the desired result may be readily determined and when once ascertained will be effective under all normal conditions of operation, and, as mgoing separation be of the-same or substantially the same size. Obviously, therefore,

dicated, the differential movement usually imparted to concentrator tables will be effective in advancing the separated bands of the different minerals forward over the table and out of the influence of the sepa rating liquid stream or sheet, so thatthe dif- 1 ferent mineral elements may be separately collected. I

Obviously it is not possible to grind or crush minerals of this general character to reduce all the elements thereof'to grains of the same uniform size, and it is for this reason that the comminutedorea gregate is graded according to the size of the granules, and the several grades or sizin separately treated on the separating ta ies for the 'reason that the successive separation of the different mineral constituents into bands is dependent upon the condition precedent that the grains, granules,' or particles underseveral sizing tables may be provided to receive differentsizes or grades of the comminuted ore, so that the entire volume of a .in one quartz constituents thereof separately collected from each tablei In the accompanying drawing aschematic diagram of a plant for puttingthe method aforesaid into practical operation is'illus- 'trated- In the diagram the crude ore is represented as being passed through a crusher, which breaks up the larger elements of the ore toadapt' thesame to be uniformly fed to a suitable comminutin -machine.- Preferably thejcrushed, ore is. elivered to storage bins, from which it may be taken by automatic feeding means, which deliver the crushed ore to the comminuter, whi'ch' latter may be any of the well knownwet ty e machines, or mills capable of reducing .t ,e ore to a state of comminution which .will insure the cracking or separation ofthe quartz and feldspar from the matrices as separate grains 0r granules otquartz'and felds; ar respectively, and similarly crack from the sizing e secon chine of appropriate character,

of! or separate the other mineral constituents as separate grains. The comminuter. may be in the form of a rod mill, roller mill, or ball mill, or in 'fact any other type of mill calculated to economically produce the de- From the 'comminuterthe or grades of the comminuted ore delivered machine are separately fed to washing tab each of the sized batch'es preferably being delivered to 'a separate table, while the'overs, of the character described,

sized tgranules'or particles are diverted to 9.

other mineral elements, which it may bedesired to save, are similarly separated and collected by the operation of the table, while the waste is delivered separately. frornthe table as tailings. I Inasmuch as commercial feldspar, in its best marketable form, must-be in a state of very fine sub-division and thoroughly. dry, the feldspar product delivered from the washing table or tables is passed through a suitable drying apparatus, which will not only drive off the moisture, but will feed comminuter and thence back to the machine whence they are distributed.

ion

the product through, it under conditionsof contmuous agitation to prevent a glorn'eras rem the tion of the feldspar particles. dryer the thoroughly dried feldspar is passed through a comminuting machine which reduces most of itto marketable sizes, which are taken out by a sizingmamay be machine, the over-sized-particles being separately: discharged from the'sizing machine and delivered to thefirst commmuter for re-treatment in the entire cycle of operations following the original comminution of the ore, thatis to say, the over-sized feldspar plarticles are admixed with the ore enteringl efirst comminuter and passed through the subsequential operations. In the. alternative, the over-sized feldspar-particle's may beflpassed to the first sizingmachine followsimilar to the. first mentioned sizing and whi h I ing j the original comminuter with a fair chance thatthe majorit of such particles will be diverted by the rst sizing machine to the second comminuter, whence they are passed back in regular order to the sizing machine, and,'if of the proper size, are then delivered to the proper washing table.

The degree of comminution to which the original ore is subjected will be dependent in a large measure upon the relative purity of the desired feldspar and quartz, obviously if a practically pure product isrequired, the ore must be reduced to such fine granular condition that each grain will cohsist only of a single mineral element, such as feldspar, quartz, and any of the other minerals found in ores of this general character.

If a less pure product is satisfactory, a lesser sub-division of the original 'ore will suffice, provided none of-the granules contain coherent mixtures of the other mineral elements with the feldspar in excessof the amount permitted in the particular use to which the feldspar is to be put.

hat we claim is:

l. The method of separating quartz and feldspar occurring --in mineral aggregate, which comprises comminuting the aggregate to a degree sufficient to effect liberation and separation of the granules of the respective 1,4oaeaa which comprises comminuting the aggregate ing current, and imparting a differential movement to the inclined surface to move the respective band forward out of the influence of the washing current and discharge,

the assorted bands separately.

3. The method of separating quartz and feldspar occurring in mineral aggregate, which comprises comminuting the aggregate to a degree sufficient to effect liberation and separation of the granules of the respective minerals each from the other, assortin'g the granular pulp thus produced into classes having substantially the same sized grains, but of different shapes due to the laws governing their cleavage, washing each of the classes of vcomminuted grains on. an inclined surface, and controlling the flow of the washing medium over the surface aforesaid to cause the respective minerals to separate into bands in accordance with the shapes of the particles of said minerals.

In testimony whereof we affix our signatures.

FRANK P. KNIGHT. JOHN T. 'SHIMMIN. 

